In the use of a rotating assembly, it is desirable to provide adjacent, independent drive sections supported in rotatable relationship about a common first member for maintaining equal load sharing characteristics between the drive sections. The rotating assembly has a first member, a second annular member positioned about the first member and a third annular member positioned about the second annular member. The invention relates to nested or concentric first and second bearing elements supporting the second and third annular members in rotatable relationship about the first member and the second annular member, respectively.
U.S. Pat. No. 3,986,753, Oct. 19, 1976, issued to Lindner, discloses an annular member of eccentric configuration positioned between and in only partial contact with concentric bearing elements. U.S. Pat. No. 3,597,029, Aug. 3, 1971, issued to Marcum, discloses concentric bearing elements positioned about a central shaft.
In an orbiting radial motor, the rotating assembly, for example, is a crankshaft assembly having an orbiting or rotating member driven by hydraulically actuated slipper pistons. As discribed in U.S. Pat. No. 4,074,615 issued to Avery on Feb. 21, 1978, orbiting members are each rotatably positioned about respective eccentric throws of a crankshaft. Forces exerted by the slipper pistons on respective orbiting members cause said members to orbit in a pathway determined by the eccentric throws restraining said orbiting members. The eccentric throws provide orbiting motion of the member in combination with the forces exerted by the slipper pistons for rotating the ring gear and driving the sprocket of a vehicle.
The use of more than one orbiting section or throw connected to a single crankshaft can cause unequal load sharing between the two orbiting sections. The result is increased wear or breakage of components and a waste of time and labor to carefully machine associated components for providing close tolerances, particularly to overcome unequal load sharing characteristics. The use of more than one crankshaft to support independent throws for overcoming unequal load carrying characteristics can cause interference in space limited situations.
Therefore, it is desirable to provide independent orbiting sections about a single first member in order to overcome unequal load sharing characteristics between the orbiting sections and to reduce the length of the rotating assembly.